In contrast, the value of the axion-nEDM coupling only depends on \(f_a\) , that is, it only assumes that the axion solves the strong CP problem.
The same model independence holds for previous analyses of highly-dense stellar objects and gravitational wave prospects, which in addition did not need to assume an axionic nature of DM. These efforts led to strong constraints on the \(\lbrace m_a, f_a\rbrace \)  parameter space [1]}, [2]}, [3]},
which can be thus directly compared with the prospects for axion-nEDM searches.
